Has the human species reached a new inflection oint in our history? Data from NASA's Voyager 1 spacecraft indicates that the deep-space explorer has encountered a region in space where the intensity of charged particles from beyond our solar system has markedly increased. Voyager scientists looking at this rapid rise draw closer to an inevitable but historic conclusion – that humanity's first emissary to interstellar space is on the edge of our solar system.

"The laws of physics say that someday Voyager will become the first human-made object to enter interstellar space, but we still do not know exactly when that someday will be," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. "The latest data indicate that we are clearly in a new region where things are changing more quickly. It is very exciting. We are approaching the solar system's frontier."

The data making the 16-hour-38 minute, 11.1-billion-mile (17.8-billion-kilometer), journey from Voyager 1 to antennas of NASA's Deep Space Network on Earth detail the number of charged particles measured by the two High Energy telescopes aboard the 34-year-old spacecraft. These energetic particles were generated when stars in our cosmic neighborhood went supernova.

"From January 2009 to January 2012, there had been a gradual increase of about 25 percent in the amount of galactic cosmic rays Voyager was encountering," said Stone. "More recently, we have seen very rapid escalation in that part of the energy spectrum. Beginning on May 7, the cosmic ray hits have increased five percent in a week and nine percent in a month."

This marked increase is one of a triad of data sets which need to make significant swings of the needle to indicate a new era in space exploration. The second important measure from the spacecraft's two telescopes is the intensity of energetic particles generated inside the heliosphere, the bubble of charged particles the sun blows around itself. While there has been a slow decline in the measurements of these energetic particles, they have not dropped off precipitously, which could be expected when Voyager breaks through the solar boundary.

The final data set that Voyager scientists believe will reveal a major change is the measurement in the direction of the magnetic field lines surrounding the spacecraft. While Voyager is still within the heliosphere, these field lines run east-west. When it passes into interstellar space, the team expects Voyager will find that the magnetic field lines orient in a more north-south direction. Such analysis will take weeks, and the Voyager team is currently crunching the numbers of its latest data set.

"When the Voyagers launched in 1977, the space age was all of 20 years old," said Stone. "Many of us on the team dreamed of reaching interstellar space, but we really had no way of knowing how long a journey it would be -- or if these two vehicles that we invested so much time and energy in would operate long enough to reach it.”

Launched in 1977, Voyager 1 and 2 are in good health. Voyager 2 is more than 9.1 billion miles (14.7 billion kilometers) away from the sun. Both are operating as part of the Voyager Interstellar Mission, an extended mission to explore the solar system outside the neighborhood of the outer planets and beyond. NASA's Voyagers are the two most distant active representatives of humanity and its desire to explore.

Stephen Hawking has said that "I don't think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I'm an optimist. We will reach out to the stars."

Comments

There is more than to these observations than simple the idea that Voyager has entered interstellar space, I think. What are the implications for earth that "the intensity of charged particles from beyond our solar system has markedly increased", and that this intensity is rapidly escalating, increasing from May 7 this year by "five percent in a week and nine percent in a month"? What should we deduce from this? That more and more intensely charged particles, possibly from some galactic explosion, are approaching our solar system? That at a time when earth's protective magnetic shield has been found to be weakening, we may be due for a wave of intensely charged? Could these observations be explained by the Cosmic wave theory that is circulating these days, that waves caused by explosions at the galactic centre are headed for us? I do not mean to be a catastrophist, but clearly, we live in a cosmos that has many surprises in store for us, I, for one, am looking up more seriously than ever before, and taking notice.

There are a number of well-informed opinions in the geophysics community suggesting that despite the evident weakening of the magnetic field, it remains stronger than at most other periods in the earth's paleomagnetic record.

The surprising increase of charged particles near the perimeter of the solar system may have some bearing on the speculative notion of dark matter and dark energy.

Tosca, put on your thinking cap for a minute. There are no more charged particles heading our way than 20 years ago. The fact that Voyager is detecting more charged particles is because it's moving out of the protective magnetic field of our solar system.

According to your logic, if you were travelling north and noticed it was getting colder/snowier/icier the further north you went, you would panic and assume that back home they better start knitting wool coats and sharpening their ice skates.

It is because Voyager is exiting the Sun's heliosphere; it is loosing it's protection from the the Sun's solar winds. Voyager is at the edge of the heliosphere where the SW pressure fades by the inverse square law, Voyager is at the transitional space where the SW are equaling the interstellar pressure. The heliosphere protect our solar system from many high energy particles that travel through the interstellar medium. With Voyager starting to record them for the first time, we now may be able to measure the interstellar radiation and use that information to plan future expeditions.